50 years have passed since the events of The Library of Discord, and Accord and his friends have lived long, fruitful, fulfilling lives. But when Pinkie Pie gets sick and is rushed into hospice care, Accord makes plans to turn her—and all of Equestria—immortal.

But when the powers that actually created Equestria return, Accord will have a tough time convincing them and himself that true immortality for all is a good idea.